Strip metal dimension sensing device for metal working machines

ABSTRACT

A device for sensing the dimensions of a metal strip as it is fed into a metal working machine such as a punch press and thereby controlling the press to prevent damage. Two sensing blocks, one for thickness and one for width, are pivotally mounted on a settable slide and include two rollers which make mechanical contact with the metal strip as it is fed through the device. If the strip is wider or thicker than the set dimensions, the block is rocked through an angle. By gear means, the angle is multiplied and applied to a contact means which closes an electric circuit and stops the metal working machine.

1451 May 22, 1973 O United States Patent 1 11 1 Kroeck [54] STRIP METALDIMENSION SENSING 3,006,450 10/1961 Nash ..192 127 DEVICE FOR METALWORKING MACHINES Primary ExaminerAllan D. Herrmann [76] Inventor:Herbert Kroeck, 90 B Dale Street, Attorney-Albert Kmnman West Babylon,NY. 11704 [57] ABSTRACT [22] Filed: Nov. 15, 1971 A device for sensingthe dimensions of a metal strip as PP 198,683 it is fed into a metalworking machine such as a punch press and thereby controlling the pressto prevent [52] us. Cl ..192/127, ZOO/61.13 g Two Sensing blocks, onefor kn ss and [51] Int. Cl. ..F16d 71/00, B65h 25/14 one for width, arepivotally mounted on a settable [58] Field of Search ..l92/ 127;ZOO/61.13, slide and include two rollers which make mechanicalZOO/61.41, 61.42 contact with the metal strip as it is fed through thedevice. If the strip is wider or thicker than the set [56] ReferencesCited dimensions, the block is rocked through an angle. By UNITED STATESPATENTS gear means, the angle is multiplied and applied to a contactmeans which closes an electric circuit and 2,179,517 11/1939 Pelosi..l92/127 stops the metal working machine. 2,679,307 5/l954 Koch....l92/l27 2,960,731 11/1960 Hogg, Jr. et al. ..192/127 9 Claims, 6Drawing Figures Patented May 22, 1973 3,734,260

2 Sheets-Sheet 1 1: ATTORNEY Patented May 22, 1973 3,734,260

2 Sheets-Sheet 2 ATTORNEY STRIP METAL DIMENSION SENSING DEVICE FOR METALWORKING MACHINES BACKGROUND OF THE INVENTION Devices for sensingimproper dimensions of metal objects are known and have been used forsome time in connection with metal working machines. Generally, thesensing devices have included a simple make-orbreak electrical contactto control a relay and a stop means to prevent damage to the machines.Such measuring devices are not very sensitive an do not have theflexibility to handle large over-sized objects. The present inventionemploys a compact rockable block arrangement which can be used to senseobjects that are too large or too small. There is a fail safe slidingmeans which can accommodate objects that are quite large without damageto the sensing means.

A feature of the invention is the sensitivity of the device, providing alarge movement of the contact means with a small movement of the rollerwhich bears on the object.

Another feature of the invention is the ability of contact means toretract under excessive movements. This feature is made possible bymounting the contacts at the ends of long springs in piston-likebarrels.

For a better understanding of the present invention, together with otherdetails and features thereof, reference is made to the followingdescription taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a plan view of the sensingdevice.

FIG. 2 is a cross sectional view of the sensing device shown in FIG. 1and is taken along line 22 of that fig ure.

FIG. 3 is an end view of the sensing device shown in FIG. 2 and is takenalong line 3-3 of that figure.

FIG. 4 is a plan view, to an enlarged scale, of a portion of the sensingdevice, showing the details of the width sensing mechanism.

FIG. 5 is a side view, similar to FIG. 5, of another portion of thesensing device, showing the details of the thickness sensing mechanism.

FIG. 6 is a schematic diagram of connections showing how the sensingdevice is coupled to a load.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the figures,the sensing means is mounted on a rectangular base 10 which ispreferrably a flat metal plate. Near one end of the base 10 is thethickness sensing device 11 and at the opposite end is the width sensingdevice 12. The width sensing device 12 is mounted on a dove-tailed slide13 which is secured at one end to pivot bar 14. Rockably mounted on thepivot bar 14 is a sensing block 15 and rotatably secured to the bar aretwo rollers 16, 17, designed to make contact with an object 18, such asa strip of metal the width of which is to be sensed. Also carried by theblock 15 are two spaced, opposed contact devices and 21 (Best shown inFIG. 4). These devices each comprise a cylindrical conductive memberslidably carried within a bore 23 in the block 15. A' helical spring 22urges each of the conductive members'20, 21, to ward each other at alltimes. A first metal large gear segment plate 24 is secured to the lowersurface of block 15 and rotates with it. Gear segment plate 24 isprovided with a plurality of gear teeth 25 at its outer periphery whichmesh with the teeth on a pinion gear 26, freely journaled in slide 13,(See FIG. 2). The gear ratio between the gear segment 24 and the piniongear 26 is such that a small movement of the gear segment 24 will bemultiplied into a large movement of the pinion gear. A lever 21 issecured to the pinion gear shaft 26a by means of an insulator bushing 28and has a metal contact extension pin 30, positioned between contactmembers 20, 21. Sensing block 15 is resiliently biased by a helicalspring 31 to normally hold extension pin 30 against contact 20 as shownin FIG. 4.

The dove-tailed slide 13 is formed with an upwardly extending portion 32at its end opposite the pivot bar 14. The upwardly extending portion 32is transversely bored to freely receive and guide a second contact pin33. The second contact pin 33 is also slidably held in a block 34 boltedto the base 10. The pin 33 extends through the block 34 and its outerportion is threaded. An adjustable nut 35 is mounted at the outer end ofpin 33 and is used to set the pin at a position where a desired width ofstrip 18 may be sensed. A flange 36 is formed on pin 33 to act as a stopfor coil spring 37, which is disposed about the pin 33 between theflange 36 and the block 34. A coil spring 38 is mounted between theslide 13 and block 34. The coil spring 38 is compressed to urge thewidth sensing device toward the strip 18 at all times.

The operation of this portion of the device is as follows: Prior tofeeding the strip 18, spring 31 biases block 15 so that contactextension pin 30 makes electrical contact with the conductive cylinder20. This contact closes a circuit through a relay winding 45, to openanother contact and stop the machine action. When the sheet 18 to besensed is fed into the sensing means, both rollers 16, 17 come incontact with the edge of the strip and, if the sheet has parallel edges,the sensing block 15 is moved to the position shown in FIG. 1. At thisposition extension pin 30 does not make contact with either conductivecylinder 20 or 21 and the relay 45 is normalized, closing its contactsand energizing the machine or load 48. These conditions prevail as longas the strip 18 is of the desired width while passing through thedevice. If the strip width slowly increases, the block 15 will be forceoutwardly until contact is made between the rear surface of lever 27 andpin 33, activating the relay and stopping the machine. If a rough edgeor sudden width change is sensed, so that the block 15 is rotatedthrough a small angle, lever 27 is turned, by the multiplying action ofthe segment 24 upon the pinion 26, making contact between extension pin30 and one of the cylinders 20, 21, again stopping the machine. If thestrip 18 becomes undersized, the spring 31 will rotate the block 15causing the pin 30 to contact the conductive cylinder 20 to stop themetal working machine.

The vertical or thickness sensing device 11 is similar to the horizontalor width sensor 12 except that it is mounted at right angles to the baseplate 10. An angular support bracket 40 is secured in the dove-tailedslot in the base 10 and is formed with two slots 41 in its upstandingportion 40a for vertical adjustment. A supporting plate 42 is secured tothe angular support 40 by two bolts in slots 41 (See FIG. 3). Thevertical sensing device 11 includes a slide 13a (See FIG. 5), sliding ina dove-tailed slot and a rockable sensing block 15a pivoted about apivot bar 14a. Two rollers 16a and 17a carried upon a bar 50 are coupledto block 15a and are positioned so that the strip 18 to be sensedengages both of them in sequence. Block 15a includes two spaced, opposedcontact cylinder members 20a and 21a. As before, these contact membersare urged to.- ward each other by springs (not shown). A gear platesegment 24a is secured to the sensing block 15a and is provided withgear teeth 25a. A pinion gear 26a meshes with the teeth 25a and ismounted on a shaft 51 which is secured to an insulator bushing 28a and alever 27a having a contact extension pin 30a positioned between the twocontact members 20a and 21a. The thickness sensing device 1 1 alsoincludes a threaded vertical contact pin 33a, slidably mounted in aplate 34a and urged downwardly by a spring 370. An adjustable nut 35a isreceived upon the upper end of pin 30a. Two limiting rollers 43 aremounted on vertical stub shafts in the base and extend below thethickness sensing device 11 for positioning the right hand edge of strip18 as seen in FIG. 2.

The operation of the vertical sensing means is the same as thehorizontal sensing means. Spring 31a connected between the plate 34a andthe block a biases the block 15a so that extension pin 30a is in contactwith cylindrical contact member 21a. Then the strip 18 to be measured isfed into the sensing device making contact with rollers 17a and 16a. Atthis time extension pin 30a is halfway between contact members a and 21aso that the relay 45 is not actuated and the stamping machine 48 canfunction. An increase in thickness of the strip 18 raises the block 15a,closes the gap between pin 33a and lever 27a and actuates the relay 45.Also, a small change in thickness is sensed by the two rollers 16a, 17aand extension pin 30a is moved to the right of left to make contact withone of the contact members 20a, 21a, and stop the machine. Here again, asmall change in thickness is multiplied by the gear segment 24 andpinion gear 26.

There are many relay circuits which can be used with this sensingdevice. FIG. 6 shows one circuit where all the contact members 20, 21,20a, 21a, and the pins 33, 33a, are grounded while the two levers, 27and 27a, are connected in series with a winding 45 of a relay having apair of normally closed contacts 46. The other side of the relay windingis connected in series with a source of potential 47 and ground.Contacts 46 are connected to a load 48 which may have its own controlcircuit and its separate source of electrical power.

Having thus fully described the invention, what is claimed as new anddesired to be secured by Letters Patent of the United States, is:

l. A strip dimension sensing device for metal working machinescomprising a support base to receive strip metal, at least one rockablesensing block pivotally secured to the support base, at least one rolleron said block for making contact with the strip metal, spaced, opposed,electrical contact members slidably carried by the block, a rockablelever, a conductive contact pin extending from said lever positionedbetween the two electrical contact members, an electrically insulatedpivot means supporting the rockable lever, gear means coupling thesensing block to the rockable lever and making contact between thecontact pin and one of the electrical contact members when the sensingblock is rotated through an angle greater than a predetermined amount,and an electrical control circuit connected between the rockable leverand the metal working machine whereby over or under limit stripdimensions will interrupt the machine operations and prevent machinedamage.

2. A device according to claim 1 in which the block is spring loaded inthe direction of the oncoming strip at all times.

3. A device according to claim 1 in which the gear means coupling thesensing block to the rockable lever is a mechanical motion multiplier.

4. A device according to claim 3 in which the gear means comprises alarge gear segment in mesh with a small pinion gear.

5. A device according to claim 1 in which the sensing block is elongatedand provided with a roller spaced from each end thereof.

6. A device according to claim 1 in which the block is laterallyslidable within the support base and the support base is provided with asecond contact pin disposed in the path of the block.

7. A device according to claim 6 in which the block is spring loaded inthe direction of the strip being sensed.

8. A device according to claim 1 in which the support base issubstantially L-shaped, a first and second rockable sensing block iscarried upon the vertical and horizontal portions of the L-shaped base,a roller is freely carried at each end of the sensing blocks in the pathof the strip to be sensed, spaced opposed, electrical contact membersare carried by each of the blocks, a rockable lever is secured to eachof the blocks, a conductive contact pin extends from the said leverbetween the block carried contact members, an electrically insulatedpivot means supports the rockable lever on each of the blocks, gearmeans couples each of the sensing blocks to the rockable lever, and anelectrical control circuit is connected between each of the rockablelevers and the metal working machine, whereby over or under limit stripdimensions will interrupt the machine operations.

9. A device according to claim 8 in which the horizontal sensing blockis horizontally slidable within the support base and the verticalsensing block is vertically slidable within the vertical portion of thesupport base and the ends of the vertical and horizontal portions of thesupport base are each provided with a contact pin disposed in the pathof each of the blocks.

1. A strip dimension sensing device for metal working machinescomprising a support base to receive strip metal, at least one rockablesensing block pivotally secured to the support base, at least one rolleron said block for making contact with the strip metal, spaced, opposed,electrical contact members slidably carried by the block, a rockablelever, a conductive contact pin extending from said lever positionedbetween the two electrical contact members, an electrically insulatedpivot means supporting the rockable lever, gear means coupling thesensing block to the rockable lever and making contact between thecontact pin and one of the electrical contact members when the sensingblock is rotated through an angle greater than a predetermined amount,and an electrical control circuit connected between the rockable leverand the metal working machine whereby over or under limit stripdimensions will interrupt the machine operations and prevent machinedamage.
 2. A device according to claim 1 in which the block is springloaded in the direction of the oncoming strip at all times.
 3. A deviceaccording to claim 1 in which the gear means coupling the sensing blockto the rockable lever is a mechanical motion multiplier.
 4. A deviceaccording to claim 3 in which the gear means comprises a large gearsegment in mesh with a small pinion gear.
 5. A device according to claim1 in which the sensing block is elongated and provided with a rollerspaced from each end thereof.
 6. A device according to claim 1 in whichthe block is laterally slidable within the support base and the supportbase is provided with a second contact pin disposed in the path of theblock.
 7. A device according to claim 6 in which the block is springloaded in the direction of the strip being sensed.
 8. A device accordingto claim 1 in which the support base is substantially L-shaped, a firstand second rockable sensing block is carried upon the vertical andhorizontal portions of the L-shaped base, a roller is freely carried ateach end of the sensing blocks in the path of the strip to be sensed,spaced opposed, electrical contact members are carried by each of theblocks, a rockable lever is secured to each of the blocks, a conductivecontact pin extends from the said lever between the block carriedcontact members, an electrically insulated pivot means supports therockable lever on each of the blocks, gear means couples each of thesensing blocks to the rockable lever, and an electrical control circuitis connected between each of the rockable levers and the metal workingmachine, whereby over or under limit strip dimensions will interrupt themachine operations.
 9. A device according to claim 8 in which thehorizontal sensing block is horizontally slidable within the supportbase and the vertical sensing block is vertically slidable within thevertical portion of the support base and the ends of the vertical andhorizontal portions of the support base are each provided with a contactpin disposed in the path of each of the blocks.